** Description changed:
+ [Impact]
+
+ slub_debug cannot work for specific kmem_cache size.
+
+ e. g. slub_debug=PU,kmalloc-1024
+
+ The slub_debug is used to enable the debugging of use-after-free, poison
+ overwritten, double free. And it also increases the up time of the server
+ when the above mentioned errors happen instead of crashing immediately.
+
+ However, currently, there exists bug that the slub_debug cannot be applied
+ for the specific object size. This is not helpful to enable the whole
+ system slub_debug because the performance loss will be up to 20%~30%
+ according to the customer's measurement. The patch here to limit the
+ slub_debug only on the specific object size to alleviate the performance
+ loss.
+
+ [Fix]
+
The slub_debug=PU,kmalloc-xx cannot work because in the
create_kmalloc_caches() the s->name is created after the
create_kmalloc_cache() is called. The name is NULL in the
create_kmalloc_cache() so the kmem_cache_flags() would not set the
slub_debug flags to the s->flags. The fix here set up a kmalloc_names
string array for the initialization purpose and delete the dynamic name
creation of kmalloc_caches.
+
+ [Test case]
** Changed in: linux (Ubuntu)
Assignee: (unassigned) => Gavin Guo (mimi0213kimo)
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1456952
Title:
support the slub_debug boot option on specific object size
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1456952/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
